Chicago Fire Department officials on Thursday night released a statement confirming that CFD Deputy Commissioner John McNicholas failed a sobriety test after a crash early Wednesday.

“The investigation thus far has found that McNicholas was operating his city vehicle outside of department policy, and that following a mandatory breathalyzer test that morning, McNicholas was driving under the influence of alcohol,” CFD spokesman Larry Langford said in a statement. “Yesterday, McNicholas opted to resign his position as Deputy Fire Commissioner and has since agreed to full separation from the fire department.”

Langford confirmed McNicholas also was issued a citation from police for negligent driving.

But sources tell the Chicago Sun-Times that McNicholas is unlikely to be charged with driving under the influence because the test was not administered by police responding to the crash. McNicholas was instead administered the test by the internal affairs division of the fire department … and police are not allowed to use a fire department test because it is measured on a different standard.

Chicago Police spokesman Anthony Guglielmi on Thursday confirmed that McNicholas was ticketed for negligent driving, but he said the investigation remains open. He did not comment on whether police administered the field sobriety test and said he could not comment on any pending charges.

Police said initially that no citations or charges had been issued just after the crash, but police and fire officials were conducting a joint and active investigation.

McNicholas tendered his resignation to department Commissioner Jose A. Santiago on Wednesday and is “fully cooperative with the Internal Affairs Division,” Langford said.

According to the fire department’s last chance policy, which is in their contract, anyone caught for an alcohol or drug offense can be placed on a type of probation where they are tested randomly for alcohol or drugs for a year. If they test negative during that period, their probation is lifted.

McNicholas will not be given that opportunity, sources said. But McNicholas will still receive a pension for his 36-year career with the fire department.